Boiler protective device

ABSTRACT

A float chamber to be connected to the upper portion of a steam boiler contains a float which closes an overflow valve until lifted by water rising in the boiler to excessive height. The float moreover controls a switch for interrupting firing of the boiler when the float is lifted, and for signalling such interruption.

United States Patent Relief Pre ssure Opiela 1451 Aug. 22, 1972 [54] BOILER PROTECTIVE DEVICE [56] References Cited 72 Inventor: Jerry J. Opiela, 5942 155111 St., UNITED STATES PATENTS Flushmg 1355 2,378,883 6/1945 Russel ..417/40 x [22] Filed: May 7, 1971 2,292,648 8/1942 Moore ...200/84 c 12.1] Appl. No.: 141,390 1,914,541 6/1933 Teesdaze ..200/84 B Related US. Application Data Primary Examiner-David Smith, J1- [63] Continuation of Ser. No. 827,0l5, May 22, g"; Edmonds Taylor 1969, abandoned. a

52 US. Cl. ..200/84 B, 219/333, 417/40, [57] ABSTRACT 3 345 A float chamber to be connected to the upper portion I i 1 Int; Cl. of a st a n boiler contains a float closes an over- [58] Field of Search..200/84 B, 84 c, 84 D; 219/333;

flow valve until lifted by water rising in the boiler to excessive height. The float moreover controls a switch for interrupting firing of the boiler when the float is lifted, and for signalling such interruption.

3 Oaims, 1 Drawing Figure Boiler \VAVA PATENTED I97? 3 686, 452

Pressure 7 Relief J Valve Boiler ALARM v//& //A\ AV A \V //A INVENTOR Jn'y J. Opielcl mw wdaz w ATTORNEYS BOILER PROTECTIVE DEVICE This application is a continuation of application Ser. No. 827,015, filed May 22, 1969, now abandoned.

The present invention pertains to boiler control, and more particularly to protection of steam boilers from flooding. The invention provides apparatus which prevents overfilling of the boiler to which it is attached, and which interrupts the firing of the boiler when the water therein rises to a predetermined level.

BRIEF DESCRIPTION OF THE DRAWING The invention will now be further described in terms of a presently preferred non-limitative exemplary embodirnent thereof and by reference to the accompanying drawing in which the single figure of drawing is a view in side elevation, partly cut away, of a boiler protective device in accordance with the invention, shown in association with a diagrammatically indicated boiler, firing unit, pressure relief valve, and alarm device.

DESCRIPTION OF PREFERRED EMBODIMENT In the drawing, a boiler is diagrammatically indicated at 2, with a firing unit therefore at 4. The boiler is provided at the upper end thereof with a fitting 6, to which a pressure relief valve 7 may be fitted. In accordance with the invention, the pressure relief valve is replaced at the fitting by a float chamber 8. The pressure relief valve may then be mounted above the float chamber as indicated in the drawing, and connecting with the interior thereof as it connects with the interior of the boiler when mounted directly on the fitting 6.

The chamber 8 contains a float 10 connected by means of a flexible coupling, shown as a bellows 12, to the wall of the float chamber. By means of a stem 13 the float also carries, on its underside, the closing member 14 of a valve generally indicated at 18. The valve includes a seat 16 formed at the end of a conduit 20, leading to an overflow pipe 22.

A rod 24 affixed to the float 10 passes to the exterior of the chamber 8 through the bellows 12 and carries at its end a switch 26. The switch is shown as a single pole, double throw mercury switch, although other types may be employed.

The switch contains a common terminal 28 and two additional poles or terminals 30 and 32. So long as the water does not rise through fitting 6 into the chamber to lift the float, the float is supported on the valve member 14 which thereby keeps valve 18 closed. At thesame time terminals 28 and 30 are short-circuited together by the mercury in switch 26, while terminals 28 and 32 are open-circuited.

The common terminal 28 of the switch is connected to a conductor 34 in an energizing or control circuit of the firing unit 4. Of the other two poles or terminals, the terminal 30 connects to another conductor 36 in the same circuit as conductor 34, and the other pole or terminal 32 connects to an alarm device 38 and thence through a source of potential 40 back to the terminal 28 The circuit including conductors 34 and 36 and switch terminals 28 and 30 is arranged to permit energization of the firing unit 4 so long as contacts 28 and 30 are short-circuited together.

Thus so long as water does not rise into the chamber 8 to lift the float, the valve 18 is kept closed, permitting maintenance of steam pressure in the boiler, and the $l l8fi r a l illll i ifd lfit'l l% an35li%l switch 26. When however the float is lifted by the rise of water from the boiler into the float chamber, the float is lifted, thereby opening the valve 18 and permitting excess water to pass to the drain 22. With lift of the float, by an amount which may be adjusted by positioning of switch 26 on the rod 24, contacts 28 and 30 are moreover open-circuited, thus interrupting the operation of the firing unit. The same or a different amount of lift for the float moreover short-circuits the switch contacts 28 and 32, energizing the alarm device 38.

The relation of the switch contacts to the firing or fire control and alarm circuits is of course not limited to that which has been described. The circuit connections may consistently with the invention be such that firing is interrupted upon short-circuiting of one pair of switch contacts while the alarm is activated upon opencircuiting of another pair of switch contacts.

The invention thus provides simple and effective apparatus which prevents overfilling of a steam boiler and consequent damage thereto and to its surroundings, and which also safely shuts off the firing of the boiler in such event.

I claim:

1. A boiler protective apparatus comprising a boiler, a float chamber positioned above said boiler, means for providing communication between said boiler and said chamber, said communication means permitting the flow of water from said boiler into said chamber upon the rise of water in said boiler above a normal level, a float in said chamber, said float being raised upon an excess accumulation of water in said chamber, a drain pipe leading downwardly from the interior of said chamber to the exterior thereof, a valve controlling communication between the interior of the chamberand aid drain pipe, and means coupling the float to the valve for opening of the latter upon raising of the float thereby permitting the drainage of excess water in the chamber away from said apparatus upon lift of the float.

2. The boiler protective apparatus of claim 1 further comprising a switch coupled to the float for actuation thereby.

3. The boiler protective apparatus of claim 2 wherein said switch is of a single pole, double throw type with its common terminal connected to one pole for the closed condition of said valve and with its common terminal connected to the other pole for the open condition of said valve and wherein one pole is connected to the firing circuit of the boiler and the other pole is connected in an alarm circuit for the boiler.

P0-1050 I UNKTED STATES PATIENT @FFKCE CERTEFECATE @lF @QRREQTEQN iatent No. 3, w-5 Datecl August 97 Inventofls) Jerry J9 Opiela It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

I' I? Cover page right-hand column under "References Cited'k for "Teesdaze substitute -Teesdele w Column 1, line 2% for Wherefore ,substitute --sheref-or-m Column 2 line M5 for 'aiol" substitute --said.--=o

Signed and sealed this 23rd day of January 1973.

Attest: I EDWARD MQFLETCHER TR ROBERT GOTTSCHAIIK Attesting Officer Commissioner of Patents W0 UNITED S'IA'iES PATENT orrrcr MA CF CUECTN Patent No. 39 9 5 Dated August 9 97 Inventor(s) Jerry J. Opiela It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Cover page, right-hand column, under "References Cited", for

"Teesdaze" substitute ----E[ees(iale---m Column 1, line 2 L, for therefore" substitute --theref-or--. Column 2, line M, for "aid." substitute "said",

Signed and sealed' this 23rd day of January 1973.

(SEAL) Attest:

EDWARD MrFLETCHERJR. a ROBERT GOTTSCHAIIK Attesting Officer Commissioner of Patents 

1. A boiler protective apparatus comprising a boiler, a float chamber positioned above said boiler, means for providing communication between said boiler and said chamber, said communication means permitting the flow of water from said boiler into said chamber upon the rise of water in said boiler above a normal level, a float in said chamber, said float being raised upon an excess accumulation of water in said chamber, a drain pipe leading downwardly from the interior of said chamber to the exterior thereof, a valve controlling communication between the interior of the chamber and said drain pipe, and means coupling the float to the valve for opening of the latter upon raising of the float thereby permitting the drainage of excess water in the chamber away from said apparatus upon lift of the float.
 2. The boiler protective apparatus of claim 1 further comprising a switch coupled to the float for actuation thereby.
 3. The boiler protective apparatus of claim 2 wherein said switch is of a single pole, double throw type with its common terminal connected to one pole for the closed condition of said valve and with its common terminal connected to the other pole for the open condition of said valve and wherein one pole is connected to the firing circuit of the boiler and the other pole is connected in an alarm circuit for the boiler. 